Class to handle mail queue managment.
Wrapper for PEAR::Mail and PEAR::DB (or PEAR::MDB/MDB2). It can load, save and send saved mails in background and also backup some mails.

The Mail_Queue class puts mails in a temporary container, waiting to be fed to the MTA (Mail Transport Agent), and sends them later (e.g. a certain amount of mails every few minutes) by crontab or in other way.